Referring to FIG. 1, an exemplary heater treater 10 is shown for heating recovered oil well fluids so that the oil can be accepted by the pipeline. Such heater treaters 10 facilitate the breaking of oil and water emulsions and facilitate the separation of oil, water and gas.
The heater treaters 10 typically employ a heater treater vessel 12 that may be oriented vertically, as is shown, or horizontally. A fire tube assembly 14 is formed as a continuous U-shaped conduit or fire tube 16 that extends into the interior of the vessel 12 for heating of well fluids within the heater treater vessel 12. A burner/igniter 18 is provided at an inlet 20 of the fire tube 16. The burner/igniter 18 may be mounted at the inlet 20 through endcap 22 that is bolted or fastened to a mounting flange 24 at the inlet 20 of the fire tube 16. The inlet 20 receives fuel gas from fuel line 26, which is ignited and combusted within the fire tube 16 by means of the burner/igniter 18. Hot combustion gases pass through the fire tube 16, as indicated by the arrows 28, to facilitate heating of fluids within the heater treater vessel 12. Exhaust gases are discharged through outlet 30 of the fire tube 16 and exhausted through exhaust pipe 32, which is shown connected to the outlet 30 through conduit elbow 34.
The fire tube assemblies of heater treaters, such as the fire tube assembly 14, must be maintained and replaced often, requiring frequent removal and installation. Currently, installation and removal of the fire tube assemblies, such as the assembly 14, is a difficult process. The fire tube assembly 14 is fairly large, typically having a length of 4 to 6 feet, and typically weighs several hundred pounds. The fire tube assembly 14 is secured at a proximal mounting end to an opening in the heater vessel 12 by means of mounting flange 36 that surrounds the opening formed in the vessel 12 and to which the fire tube assembly 14 is bolted or fastened and thus supported. The opposite distal end 38 of the fire tube 16 projects into the vessel 12 from the mounting flange 36 and is typically free or unsupported.
To facilitate removal and installation of the fire tube assembly 14, with the exhaust conduit 32 uncoupled from the elbow 34 and the fuel line 26 uncoupled from the inlet 20 of the fire tube 16, as well as other structures connected to the fire tube assembly 14, a line, rope or strap, which may be attached to a hoist, crane or other support structure, is commonly secured to the outlet end 30 of the fire tube assembly 14 to facilitate its removal and installation. When the fire tube assembly 14 is unbolted or unfastened from the mounting flange 36 of the heater treater vessel 12, the free or unsupported end 38 of the fire tube 16 will tend to drop or dip down within the vessel 12 so that the fire tube cannot be passed through the opening of the vessel 12.
To control the fire tube assembly 14 during installation and removal so that it remains level and the free end of the fire tube 16 does not dip down, oftentimes, workers will remove the end cap 22 of the inlet and insert a long length of oil field pipe (not shown) into the inlet 18 end of the fire tube 16. The length of pipe may be very long (e.g., 25 feet) to provide sufficient leverage for a worker or workers holding the opposite end to facilitate handling of the heavy fire tube assembly 14. With the fire tube assembly 14 supported by the hoist, a worker will manipulate the length of pipe so that the fire tube 16 remains as level as possible when uncoupled from the heater treater vessel 12. While the distal end 38 of the fire tube 16 may undergo small movements during installation or removal, the movement of the free end of the pipe (not shown) is much larger, creating safety concerns to those nearby if the inserted pipe is not fully controlled.
Furthermore, because the inserted end of the oil field pipe is much smaller in diameter compared to the diameter of the fire tube 16, the inserted end of the pipe will tend to move around within the fire tube 16, hitting and striking the interior walls of the fire tube 16, which may cause damage to the fire tube assembly 14.
Additionally, for each oil well, there may be as many as three to six heater treaters, which may be spaced fairly close together (e.g., 10 to 15 feet), with each heater treater having a fire tube assembly that may need removal and replacement. Equipment and other structures (e.g., oil field equipment and vessels, containment berms, fences, etc.) surrounding the heater treater 10 may also be located nearby. Thus, in many instances there may not be enough room to insert such a long length of pipe into the fire tube assembly 10 to facilitate its control during installation and removal.
Accordingly, a need exists to overcome the aforementioned shortcomings.